Well... it depends on your cruising style for sure and what else you have for charging.
But generally I would say yes ....with a 75 amp and good external regulator
.. will likely give you a lot more amps stored than the stock unit.
or...At about 100 amps single
belt you will be into a lot of V belt dust and replacement likely (not always).
Or.... if you are really into making a lot more amps, then a double belt arrangement or new style belt and big unit can be done... but if you are hesitating doing anything, then it doesn't sound like you need to go that far at all.